This invention relates in general to a rapidly-deployable lightweight tubular arch load resisting system capable of resisting loads both in the vertical and horizontal directions, useful for the rapid construction of buried arched bridges, tunnels, underground storage facilities, hangers, or bunkers, which minimizes the need for heavy construction equipment at the site.
In the past, there have been several types of technologies that have been used in order to construct short and medium span buried arch bridges, as well as some underground storage facilities and tunnels. These structures are typically covered with a soil overburden which receives traffic or other loading.
One technology includes the use of precast concrete structures which are made in one location and then shipped to the construction site. While the precast concrete structures are made skillfully and meet the construction requirements, the use of precast concrete structures adds greatly to the cost since it is expensive to ship and then install the precast concrete structures. While the precast concrete structures are somewhat quick to install, the precast concrete structures are very heavy and require heavy equipment at the site.
Another technology includes the use of cast-in-place concrete structures which are formed at the construction site and then lifted into place by cranes or the like. This cast-in-place technology provides the benefit of not having to ship the structures. On the other hand, the use of cast-in-place is also expensive and time consuming since an on-site concrete plane must be first constructed at the construction site. The cast-in place concrete structures require time-intensive and very expensive erection and removal of formwork, placement of reinforcing bars, and long construction lead times.
Yet another technology includes the use of pipe metallic structures. Metallic pipe structures have reduced life spans due to corrosion. Another drawback is that pipe metallic structures are limited to short spans and light loads.
Each of these existing construction method technologies has significant disadvantages that are overcome by the present invention. In addition to the need for heavy equipment for construction at the site in order to construct and then erect most bridges today, a major drawback that is common to these existing construction technologies is that, while metallic and steel reinforced concrete are widely used and accepted in the construction of many structures, the reinforced concrete structures are susceptible to deterioration. Over time, particularly in northern climates, numerous freeze-thaw cycles and the use of de-icing chemical accelerate corrosion and material degradation. The exposure of the steel reinforced concrete structures to conditions such as water, road salt and the like, and the freezing and thawing thereof, can cause cracks to form in the structures. These cracks, in turn, cause reinforcing steel to corrode and expand, causing further cracking, thereby allowing air and more water to enter the structure, thereby weakening and damaging the structure.